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Modeling and Calibration of Gaia, Hipparcos, and Tycho-2 astrometric data for the detection of dark companions
(2024-03-28)
Hidden within the Gaia satellite’s multiple data releases lies a valuable cache of dark companions. To facilitate the efficient and reliable detection of these companions via combined analyses involving the Gaia, Hipparcos, ...
Predicting Cloud Conditions in Substellar Mass Objects Using Ultracool Dwarf Companions
(2024-02-29)
We present results from conducting a theoretical chemical analysis of a sample of benchmark companion brown dwarfs whose primary star is of type F, G or K. We summarize the entire known sample of these types of companion ...
Mitigating Modal Noise in Multimode Circular Fibres by Optical Agitation using a Galvanometer
(2024-01-02)
Modal noise appears due to the non-uniform and unstable distribution of light intensity among the finite number of modes in multimode fibres. It is an important limiting factor in measuring radial velocity precisely by ...
Ultracool Spectroscopic Outliers in Gaia DR3
(2024-01-01)
Gaia DR3 provided a first release of RP spectra and astrophysical parameters for ultracool dwarfs (UCDs). We used these Gaia RP spectra and astrophysical parameters to select the most outlying UCDs. These objects have ...
Gaia21bty: An EXor light curve exhibiting a FUor spectrum
(2023-10-30)
Gaia21bty, a pre-main sequence star that previously had shown aperiodic dips in its light curve, underwent a considerable Delta G~2.9 mag brightening that occurred over a few months between 2020 October - 2021 February. ...
The puzzle of the formation of T8 dwarf Ross 458c
(2023-06-01)
At the lowest masses, the distinction between brown dwarfs and giant exoplanets is often blurred and literature classifications rarely reflect the deuterium burning boundary. Atmospheric characterization may reveal the ...
Identifying and characterizing ultracool dwarfs ejected from post-encounter disintegrating systems
(2023-06-01)
Disintegrating multiple systems have been previously discovered from kinematic studies of the $\it Hipparcos$ catalogue. They are presumably the result of dynamical encounters taking place in the Galactic disk between ...
Ultracool dwarfs in Gaia DR3
(2023-01-26)
Context. Previous Gaia data releases offered the opportunity to uncover ultracool dwarfs (UCDs) through astrometric, rather than purely photometric, selection. The most recent, the third data release (DR3), offers in ...
A Comparative L-dwarf Sample Exploring the Interplay Between Atmospheric Assumptions and Data Properties
(2022-10-13)
Comparisons of atmospheric retrievals can reveal powerful insights on the strengths and limitations of our data and modeling tools. In this paper, we examine a sample of 5 similar effective temperature (Teff) or spectral ...
Stellar Atmospheric Parameters of M-type Stars from LAMOST DR8
(2022-06-23)
The Large Sky Area Multi-Object Fiber Spectroscopic Telescope (LAMOST) Low Resolution Spectroscopic Survey (LRS) provides massive spectroscopic data of M-type stars, and the derived stellar parameters could bring vital ...